Many electronic devices are powered by battery packs that include pluralities of individual battery cells (e.g., cylindrical lithium-ion secondary batteries) that are connected to one another in a parallel or series arrangement to achieve a desired voltage output. If excessive current is allowed to flow between a battery pack and an electronic device during charging or discharging of the battery pack, the electronic device and/or the battery pack may be damaged. Thus, various devices are used for providing overcurrent protection in battery packs. These include various positive temperature coefficient (PTC) devices and fuse devices adapted to mitigate current in the event of a fault condition. However, such devices are associated with numerous shortcomings, including low hold currents, inability to permanently disable faulty battery cells, and space requirements that increase the overall size of a battery pack.
In view of the foregoing, it is desirable to provide a mechanism for rapidly arresting current flowing between a battery pack and an electronic device upon the occurrence of an overcurrent condition (e.g., an internal short within a cell of the battery pack) while also facilitating high hold currents during normal operation. It is further desirable to provide such a mechanism that can be implemented in individual cells of a battery pack to facilitate robust and expeditious response to overcurrent conditions in a manner that permanently disables faulty battery cells. It is further desirable to implement such a mechanism in a manner that does not increase the size of a battery pack.
It is with respect to these and other considerations that the present improvements may be useful.